Dorman 603-973 Engine Coolant Reservoir - Front

Overview of Dorman Engine Coolant Reservoir 603-973

The Dorman Engine Coolant Reservoir 603-973 is designed for reliable cooling system performance in select Cadillac, Chevrolet, and GMC vehicles. This pressurized reservoir helps maintain proper coolant levels and system pressure to support engine temperature regulation.

• Constructed from durable plastic material for long-lasting use
• Measures 12.4 inches in length and 4.37 inches in height with an irregular shape
• Includes a spring loaded twist cap rated for a maximum pressure of 15 psi
• Cap and reservoir included; mounting hardware and brackets are not included
• Capacity of 1.5 liters to accommodate cooling system requirements
• Features two mounting holes for secure installation
• Clear and black color combination for easy coolant level monitoring

Detailed Product Description

The Dorman 603-973 engine coolant reservoir is engineered to meet the specifications of various Cadillac, Chevrolet, and GMC models, including the Escalade, Sierra 1500, Silverado 2500, Yukon XL, and others. Its plastic construction offers resistance to heat and corrosion, ensuring durability under engine bay conditions. The reservoir’s irregular shape is designed to fit specific engine compartments without interfering with other components.

This reservoir is pressurized and comes with a spring loaded twist cap that maintains system pressure up to 15 psi, which is critical for preventing coolant loss and overheating. The clear section of the reservoir allows for quick visual checks of coolant levels, while the black portion provides structural support. Although mounting hardware is not included, the reservoir features two mounting holes for straightforward attachment using existing brackets.

Compatible Vehicles and Applications

• Cadillac Escalade and Escalade ESV
• Chevrolet Cheyenne, Silverado 1500, Silverado 1500 LD, Silverado 2500, Suburban 3500 HD, Tahoe
• GMC Sierra, Sierra 1500, Sierra 1500 Limited, Yukon, Yukon XL

This reservoir is intended for use in cooling systems requiring a 1.5-liter capacity reservoir with a pressurized cap to maintain optimal engine temperature and prevent coolant overflow or air intrusion.

Common Issues Addressed by This Coolant Reservoir

• Coolant leaks due to cracked or damaged reservoirs
• Loss of system pressure causing engine overheating
• Inaccurate coolant level readings from faded or discolored reservoirs
• Failure of the cap to maintain proper pressure
• Coolant contamination from compromised reservoir integrity

Installation Notes and Tips

• Ensure the engine is cool before removing the old reservoir to avoid burns
• Check existing mounting brackets and hardware for wear or damage prior to installation
• Use the two mounting holes on the reservoir for secure attachment
• Verify the spring loaded twist cap is properly seated to maintain system pressure
• Refill the cooling system with the appropriate coolant mixture after installation

Quality Assurance and Warranty

Dorman parts are manufactured to meet or exceed OEM standards for fit, form, and function. The 603-973 engine coolant reservoir undergoes quality inspections to ensure durability and performance. Warranty coverage details should be confirmed with the distributor or manufacturer, as they may vary by region.